I've replaced the master cylinder for the clutch three or four times now on the jeep in the last year. I finally got a metal one instead of the plastic one and it's help up good.
Suddenly in the last couple of days the clutch goes away. It seems fine when you initially start up and start driving around, but after a few minutes it gradually sinks to the floor. I see no leaks and the fluid is full. If you turn the jeep off and wait a few minutes and start back up its a bit better but goes down again soon after driving. One odd thing I noticed that makes me worry its more than just the hydraulic part is that if you are low in the RPMs it doesn't really happen. When I am driving up the hill and shift into say third about mid rpms you can literally watch it go to the floor. Gotta get it fixed tonight and have no way to go look at it until it is home. To be clear, it's not slipping, the pedal is just going away.
Any guesses? I've got a bit of drive I have got to make this weekend and my wife has the jeep at her office.
09-20-2013 08:50 AM
Can you pump it a few times to get it back to where it needs to be?
09-20-2013 08:51 AM
Pumping it up seemed to be working for me yesterday but my other half said its not working that well today.
09-20-2013 08:56 AM
I would say that it is sucking air from the connection in the line but there isn't anything being expelled. How well was it bled? It sounds like the piston hits an air pocket coming back up the line and it just needs bleeding. Just a guess. How long does it sit at a time without the clutch being used?
09-20-2013 09:00 AM
It sits over night and then gets driven about fifteen minutes to work sits for eight hours and gets driven home. You could be on the right track I know the connection on the master cylinder moves a a bit. The pin is in all the way but you can still move the line around.
09-30-2013 08:59 AM
Well, I thought I had it fixed, it drove great for a couple hundred miles and then this morning it started acting up again. I just don't know where to start. You can be driving down the road, it feels fine, then all the sudden it feels soft, then it's at the floor, a minute later it comes back up and is good again for a bit. As long as you pay attention to it you can keep it driveable but my other half struggles with it lol. A little over a week ago I replaced the pin in the master cylinder that retains the hose and it helped. Now it's back to broken. Any thoughts?
09-30-2013 09:29 AM
Mine did this same thing shortly before my slave developed a massive leak. At first there was no leak but it would pull air in every few times I hit it and I would lose the pedal. Pump it up it was ok for two or three more shifts. Then it stopped pumping up solid but I could still get enough to shift. It lasted a few thousand miles like that before giving up the ghost at a bad time. Rush hour traffic + no clutch = no fun. Dont worry about the little bit the line moves all mine have done that. An easy test if you have the external slave is to take it off face the piston down and push it in and let it come back out a dozen times or so. If you have a good clutch again its the slave. Remember though its just a temporary fix and will stop working again.
10-08-2013 08:00 PM
Well I replaced the slave and pumped it a gazillion times until no more air was coming out into the res. Worked ok for me but again, my wife had issues pretty quick. Now it is doing something a bit different...instead of all the clutch engagement and disengagement being at the top of the pedal travel its all at the bottom, barely disengages the clutch. But the clutch comes back up where it should be as if there is no problem. I climbed in after she got home and could feel what she meant by it only working at the very bottom of the travel but as soon as I drive it all problems go away and do not repeat. But...I do feel what she meant each time she comes home and says it happened. Do go ahead and replace the master?...for the third time this year lol. What should i do next? It's such a simple system it's frustrating.
10-09-2013 05:29 AM
Does she rest her foot on the clutch pedal. That would keep the throwout bearing slightly engauge which could be heating the fluid up.
10-09-2013 07:51 AM
Sorry, but I cannot see any jeep info on my phone. What engine, trans and year are we here? Masters normally have different problems then your new one. How exactly are you bleeding it? Just the old pump all day? Or are you getting help and bleeding it like you would brakes? And I see what siva is saying, plus that is also putting premature wear in your TOB etc. I've tangoed with the hydro system before, it's not fun. But, there is only so many things it can be.
10-09-2013 07:52 AM
She says she doesn't. I'm driving them around town this morning to see what happens. I believe her, seen that it was obviously funky for her when I get in, it just doesn't happen to me.
I'll probably grab a new master cylinder on the way home. It's really the only option left unless the hose has a crack which I see no evidence of.
PS...I'm the one with the bad habit of resting my foot on the clutch ;-)